a. Field of the Invention
The invention relates to a backlight module.
b. Description of the Related Art
FIG. 7 shows a schematic diagram of a conventional backlight module. Referring to FIG. 7, a backlight module 100 includes a back plate 102, a light-emitting element 104, a first heat-conductive pad 106a,, a second heat-conductive pad 106b,, and a heat sink 108. In the backlight module 100, the heat generated by the light-emitting element 104 is conducted through the first heat-conductive pad 106a,, the back plate 102, and the second heat-conductive pad 106b, in succession and finally to the heat sink 108. Such heat conduction path results in extremely high thermal resistance, and thus considerable heat is piled up in a local area to reduce the efficiency and operating life of the light-emitting element 104. Besides, when a large amount of heat is conducted to an optical film (not shown) via the back plate 102, the optical film is deformed or deteriorated due to high temperature to result in inferior optical performance.
Hence, some designs are proposed to solve this problem. For example, as shown in FIG. 8, Taiwan patent no. M286937, discloses a backlight module 200 where a through hole 202a, is formed on a back plate 202 at a position corresponding to an LED unit 204. Hence, the LED unit 204 is allowed to penetrate the back plate 202 and directly touches the heat sink 208 to improve heat-dissipation efficiency. Besides, Taiwan patent no. M309684, and Taiwan patent publication no. 200719028 also disclose similar designs where a through hole 202a, is formed on a back plate 202 at a position corresponding to a light-emitting element.
However, the above designs fail to both provide competent heat-dissipation efficiency and prevent heat from being conducted to a back plate.